In this example, the vars plugin is used to define the "food" hash.

vars:
  food: 
    - { key: 'fruit', value: 'banana' }
    - { key: 'fruit', value: 'orange' }
    - { key: 'veggy', value: 'onion' }
    - { key: 'veggy', value: 'pepper' }

Let's say you are using the set_fact module to define the "foo" variable, the with_items parameter to loop through the hash, and the when parameter only return items in the hash that contain a certain key or value. In this example, the "foo" variable should contain a value of "apple".

- name: set_fact to apple
  set_fact: 
    foo: "{{ item.value }}"
  with_items: "{{ food }}"
  when:
    - item.key == 'fruit'
    - item.value == 'apple'

Which should return the following. Notice the skipping lines are showing the keys and values.

TASK [set fact to apple] 
ok: [server1.example.com] => (item=apple) => {
    "msg": {
        "key": "fruit",
        "value": "apple"
    }
}
skipping: [server1.example.com] => (item={'key': 'fruit', 'value': 'banana'})
skipping: [server1.example.com] => (item={'key': 'veggy', 'value': 'onion'})
skipping: [server1.example.com] => (item={'key': 'veggy', 'value': 'pepper'})

If you would like to suppress the output, the no_log: true parameter can be used.

- name: set fact to apple
  set_fact: 
    foo: "{{ item.value }}"
  with_items: "{{ food }}"
  when:
    - item.key == 'fruit'
    - item.value == 'apple'
  no_log: true

Which should return the following. However, this will make it difficult to debug, since "None" will be returned.

TASK [set fact to apple] 
ok: [server1.example.com] => (item=None)
skipping: [server1.example.com] => (item=None)
skipping: [server1.example.com] => (item=None)
skipping: [server1.example.com] => (item=None)

The loop_control parameter can be used to limit the output to only the item being parsed.

- name: set fact to apple
  set_fact: 
    foo: "{{ item.value }}"
  with_items: "{{ food }}"
  loop_control:
    label: "{{ item.value }}"
  when:
    - item.key == 'fruit'
    - item.value == 'apple'

Which should return the following. Now you still get some valuable data being returned that can assist when debugging.

TASK [set fact to apple] 
ok: [server1.example.com] => (item=apple)
skipping: [server1.example.com] => (item=banana)
skipping: [server1.example.com] => (item=onion)
skipping: [server1.example.com] => (item=pepper)