SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37cca83f59cb4856f474395e3e0be9004dda456a3d9765656199d929ddb53e6c' 
  AND token = 'hjfZJjv2uhfg85T1tsLgCYPHhWzrggmjrHtOl+ZCX38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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