SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55108ff4b30b295b655ed8f657368668a94d917425a664c20b3a492c03982b11' 
  AND token = 'nwzV5YOTAMI85/xZ45YpsKs6RdA8j+pYFqNrXiTVY0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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