SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '27c59fa60218a9e80fa89a24dc58a5b879a9281c398403728f00b189fabe9f5d' 
  AND token = '/UIbZNIJAwvZAlm+Jrnjqt6DKmzjy6pm366LKQeS0Wo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}