SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3e68b83ca40386f6029dbcc722a6d3b5a605ff211aa099621fb8b72f9759dda' 
  AND token = 'KrHhwj6q4e51DFmQYbom4B645/V0j7g1i3oz4qjL38c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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