SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5c846423eda812beea96b040cf3e17bd989a67201b407f76ddedf5328090ed8' 
  AND token = 'AiD5lOQB6uxxjcrJvc3vp4J4wzLqghLoERCHx+Vsz1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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