SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a79b237cb6f2c07c5827177f0cb2a4283d4a462ee407d7921a60b58ab5296d2' 
  AND token = 'jy5QQeRfqeX+iRpMZSrKGiVeIhvKoUNGGnZ0yJJggJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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