SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf18ff46c103cea09e1c5a60526ac64cf27efa0619d1eb65ef9894c3450f5374' 
  AND token = 'cO4QKj7HQz6qTBudLICyYhgjvsK48e8XBotXioHeRsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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