SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4353dda9b60192dce648f7ff6080382c6dd45adc394a8742589dffb14bec931b' 
  AND token = 'OQeKqLfVB5EvXs2tW4iBOdPK2Y8RXEGANkRo7+iSDXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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