SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '58eb2b165458fb1f8ffaf1c9f858887cea7de32cfa6cf14a8b27649eb8ae7208' 
  AND token = 'Tm5lKbmNHi47ndRHEnf4Ngz0XQPVd0ir2nZVrNjmY5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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