SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a4697dfa0dfa0c5e027959ec2599094ce42e4f79ef99a5be1abc66bd5a9afe91' 
  AND token = 'qmq/Tbw+hgRgYL3xxGlHiKCEHUU4P1+KvEL7+zHZZk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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