SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcdda571453189914890b81e7ebb89b05d2d2ad79e556c20bafcc680955e1a4f' 
  AND token = 'TXJenfBL5NVHaDV7fnVIYrqY8lN4vMJ8tJLqD5H7S5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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