SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c5e3daaf0887cd428469c6527a60d29a71efff9e403e3fff446eeafd30dc54b' 
  AND token = '0yeKIvkhtduuVviA1jIZ32Om+aOtK4iYYV7/5/MAj4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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