SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '424e86a2325af9a256cf037e896a00726208b3a5e678e533ba13970c2801e8c6' 
  AND token = 'EkiJ5vXWQItKVAXDzyHmGOcOhYcl7YZdlFLjyWh5KO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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