SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7788a450800f234c24194b3f51bbafa26163b1eafe6ab435dcf79a0da5ee632f' 
  AND token = 'hvR01TOeXQ9wWNzkAFThd2ODoYP8qHo1bSkU+trrDP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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