SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf370b4197c0fe1e76522fbb76353a356d2165f5b7a1ed17120584746a9d2f0' 
  AND token = 'xNf2uzY0YEKLMG4S8pUA2m5MeLpttR+7pmdJawB2LpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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