SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4fb921e927c8cef8c741dc377e6387df0fb81e62a272e9c91fd8aa4af03e9e5' 
  AND token = 'iKWsOdGbvrWa2uowf2gfzCcsJtf1fcjcmcPRYSraPOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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