SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d4abe3621bce62a9c0bc74c65d96d7508371067246bd07308fac36b86a3a772' 
  AND token = 'D/EcdBG9a92ap21V0jiG6oI47WsHdAkRKhHU2AHu8vo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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