SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a413ecac07e82b6c19a4c67e8e49727fd8140dd2dfa1b41462959372a88679da' 
  AND token = 'GSbP6oQ7xejJfozqh50ZMB5fV+60RHgbqrHY+J/kzmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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