SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3367fd11f58c6fc288abfc47f05537ddd8c9de235d6b40314985a4cfbdfda402' 
  AND token = 'w14Y11tW4ql6mECVdNHNft95i8C8qbAK2rQuCqwWv/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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