SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da3b2368b72d05277d752a431abecd1b602c045618bba3684eed00cf1effe9f3' 
  AND token = 'Jue/awyi8+RtXSAZFaPwcqO/B8Zo5Kexa1XK9FS97yw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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