SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd847dc4430135230a6caa48b9edc5ccade51bb1bdcfa2ab02186348ad4c501e3' 
  AND token = 'aaVm3Xdu8+sS8MBDs3VIcOF7YtARIB6fKYsLMCeauxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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