SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44f72be594f0fe3abb96bebed03b94024ca1cb683806ecf83542e94ec952e91a' 
  AND token = 'Iu7ZqE1cUN9/n7+eXaigfwphdC98D2jtoqhZGQHL+j4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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