SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '886ac94305d2f642a3176538f919d175b1831c5f44d11967c490a3217572c053' 
  AND token = 'IPjb6UadqNO7qgmOdZTtAT0DLBpUg6Kfk/FV1Kykphs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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