SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9297bce65f3f623abda715cfa10f6e5d0744a15b4d524a430db861bd5603375' 
  AND token = 'gdg1zIX6uV23qYB4yQfEyAeQIpvB/mmcrhBE7Zv59xU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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