SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cacaa052f3e9cd324ce6a684007eddacfd608a2ea9376ab7a029eed0954fa5d' 
  AND token = 'rmX8EIw01AUk9Z3xIND+88UieYBl9iSKFZNnJ+2UbfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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