SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aff78b59af5f77b6b32cd1d4e4df843019427042706f8787395aa48b44b9d88' 
  AND token = 'k5jQRbYzvS0OIRNQN02VUgMtCRV3JwLpOu7WxUQZfD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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