SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d18c3c3458b2e8f565d0392fac92515a4a69480b3a88e225cf467a92591988f' 
  AND token = 'oXwhyzreFbc15rJiWVpFXD1iK7TbgmhQl4jhGI+4lkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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