SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceb99325df53ee522bc12ee89cc88720a1fc98d07ee99d141a76a780b62fa234' 
  AND token = 'k1Nq0VTK7fX2vHqO5vl86zopZbUKK8xBnJ22jYi8e44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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