SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42867cfdc141fae0d1b645d96298cd064e087668143b065edd8065d0eb21162e' 
  AND token = '8XxCMdc94g9j3YZnDA7vK3HsrURwar/Vqj8ydOLLThA=' 
  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"
    }
  }
}