SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47d97798551b8a056448a4f5c482925280b2a74c79a6979584a561f2a691a8d0' 
  AND token = 'c4em6f2QYZQXYDxgL6Z+G6ISOzz0X6LLl6oZEu04/f8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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