SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03a1418344e2510b264086953e8dd609ecbc01b19d001bf2276769197e138966' 
  AND token = 'PnUbHQoY4MJrkust9FwhHgpsWHBLzVJcEbvDoJgRRNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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