SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03e308e1908f4c7b473c30aaee8ccaf1f86e40911252cc6b1a35759e74d287ba' 
  AND token = 'hjbkyYZvBoN+ofbYdgzj6Tfhol1ih7KvK5SP3dyVHuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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