SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6df705ca520e119f02dfe0727fc0723ece9de2d03aae0322157d03b33473993' 
  AND token = 'ctb2onbZWvsgOD4bLZPW/oMutw4HMaXlrG+KmU4HYLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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