SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24831639b3541ed6036273ad53c32ab197050f66808a0db5ff970b16e33fc716' 
  AND token = 'ov+/3Z5nyBPEDfV5lzxIpFFL3qJAHYLAmlV2EuZZ8Dc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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