SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3dd6f8b7c465f6c9d6a33dac8be491bd4b39ab49a386cb2e8f51790f1c40f75f' 
  AND token = 'dznRcnepHnQgiUbdUrTKJ8KzvCVIvVUFusrJ8hSmQOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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