SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41f2418b8dbf1bfe1d862e49f54f60479b72fdd2a02086cbf69ee84dbd6d36a3' 
  AND token = 'ApGLJS+/DxXAwaKvfwCvGmANQ8NYBka1Lnp3PP4Bkjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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