SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5971c096a3446cd1b8ec983290f10664784cb1e96ae31182fb9affdd72b2c0ea' 
  AND token = 'gvrBv/AukxijMqxguhqFIebhTv5mmxfpBwQwfZyVvkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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