SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aeb4f69aacbefc540e9c2e9fa23979b66596f844c1fe9afeee995509106f368' 
  AND token = 'jRYDkG+SqxbBcy9kYOQS/LCxiPyo7WZjsrpAbo33ilI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00100

JSON explain

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