SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da7b8c541cc11036d3a64e60c6ddfe343d4f370d316f93caf936283e2bb95ef8' 
  AND token = 'hRgeoglKRxb331z7TMrVGBMrseEWAmbSoAjfpFKIqMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}