SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4813317e061003313259ba6717022a56b98c688ffa786562baaa12eeb167d3ed' 
  AND token = 'U7CtIn2paUUf7iWMZxihgIX/UzgvWdiW/kUGl4OvM1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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