SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ed131a50b8a198fdcf832b3110809a82fe317093fe528d94f09b4463c144768' 
  AND token = '5Ku0iGAxinWDrxcFGBiAJxxy8eJqQk4xTZI/6l+/H10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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