SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98bb90594746b81c3e16ec6633524ff15af1c0fff330de999275d6c448fef8d3' 
  AND token = 'oFPPNrcnce+FR+wPsV//LoWuqKQgeEKDcQ39ubrTDGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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