SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f53cd750fd0b30017dca8686b19041c278698f78a9948e137152725b13cc489a' 
  AND token = 'buZyC0gV6xht4wjU/Py5GRZpxJyBdRcyO+JDCFBR/QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}