SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9caeea5d0d7b16996d54a7387f6352378904e4cb00039d7cb4703786895cbc36' 
  AND token = 'NT11LgAwl9e/WCuHyr09RHLNfIT5r3CEHoUAs0+smWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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