SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f00e2fd68f8e2d073aa44d6d851be4ddd2d6f9890985aa3f8d68077e727ab70' 
  AND token = 'yQBnNgl3VPTYiQuEhzzEUVGmpHhpWwujOml7fTktgwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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