SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ab6f7762ddd6533eeffb215c32a85137bf572025404ff48105bbe2692e444c5' 
  AND token = 'kp+H1EZq5CljupB/1zjqIT8pg+clc4qgVvSdMy/uNzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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