SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e7c1ed6e3ff76d7fa33058b2bb781b862d001eb49cb7c4ca62893cd09c19a760' 
  AND token = 'gFSoiZlXB38mYbfFC3KCQff5k3hFpWO7yGqfBeDawyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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