SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '536fc158f5264d6acb3dd9b722e917310e478b8f161f6853b8b7d4c243abf4cb' 
  AND token = 'OTeK71QDE/+QPHBpTr3lz6BVEkoAhvk+3WgWQHQwFa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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