SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114eb6c90f72d8c353e012f316316c282cf46d24305b2df8eb970cd1a5f1f6f7' 
  AND token = 'HBHkP8gLydkRdnYQhDx3D+uvhob2d2UCu/xWJVpHWHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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