SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '598b60253db89857061c039e65260389612b441321a259289f874f7e98041ac7' 
  AND token = '27G7xMN8r5OVbxPlVcmA0W5NfnQlK5nx7IABTp1PfLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}