SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03e094b9ca6ccf3060ee74f40f54145b7dcd5e67acfab1ec8d681a351209b824' 
  AND token = 'nTUtl2rLGWWGIpAuHgjaAk206NH5BSGw+Zw+bhTnJWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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