SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcbfec33560883dfd6b0467f64595dca87732bfaa1f6654efcd02ad43e4713f6' 
  AND token = 'B0cNP+lTh9ANSFrCOvHgahWm5WXVb7Mg8WMQqcOxeVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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