SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9288982aa5dee7cf41f136caca097f1300d34a15ebea63e2ad9042f2e6894fd1' 
  AND token = '2f/ihLK9UEsdeAXbIUdEPrN/LYOaOKpFoSmKhG18CA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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