SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36c2dc928698d713dab682f8edada2864a70e7ac31269ceb89df89588dd0e4bf' 
  AND token = 'SviJKTveLhMlw/qwok7lQk0sIGuPYuEwbXD3GFsFyFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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