SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b6343ba2f047c326978613a4b27e05c79b66a234cd6af68159ccac1bf7148e3' 
  AND token = '4ehCQMEpWTmNYXkgDr/6bYhjnDZWlFP7mmJycPBqvC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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