SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19599db20325bf6caefad4ace5b82790f2d28d2638cad9795f8afd628e5f3108' 
  AND token = 'dK7ZED9qVIyvBA4fBcv3hioY3SCNuZL0XSPoZdxeN+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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