SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4915eb8c6c20f1ca409e227833ad58f9d0252cdf3899d364b6520bd86ac5d1d7' 
  AND token = 'S6DMuyA53gy0unA6Y3rDKQgE5qr3xV4qvE0jmPwxhcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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