SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '896fc8a454f4c6308531c3df159c8b90f503ae1fb32f49f7ea215178c3819a26' 
  AND token = 'mN37TI0rlPaUCF/b5wuBjxL0GRu42Z6LRmKgyPophvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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