SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1dfb9e8b9c98cea12f735d11d4bafe600b1c2bf6a62bb1c71d84fd7a40ed5f8' 
  AND token = 'ButUzsz9jaVzTmWd+U3JZWLZs+qjLRyammSv5iF4vxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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