SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf763a267c6db2d9560b49054c64cde49f74b692cf431720726eaadb6888183' 
  AND token = '5jPWxXEBKlEc6aZuTNjWX/e6LCgERFL/zaHYRqI7GTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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