SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f7cbee2dcf1ab6bca22ccfe155feff124830dd61176dd3cf35db3e451bc7eac' 
  AND token = 'uGUdQXonSU+/JBAffM/FqiHy6nAa68Jnc+Nw2Wcl4yU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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