SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39c4bb4efd3aa1a790f8ababdd6caa80e1562a6c4a8534fdb152c9e1d4e22587' 
  AND token = 'iKrTPioN3cYe0693vkwiVs0UF8Xpt6coMRhie+yDxmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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