SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a484982426a563c44f5d737ff476457bfb4ca96b7cfa561bef3b959890799ccc' 
  AND token = 'g0zEWKKIpMaXFacJm3A+nGEgWDCxwkcPP8dncVIgqoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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