SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3bedc502bb9149fe481a5667b1d75c468f4318b42b6837265c64f098e13386f' 
  AND token = '1APkoH2K1jdmVbMUMg/I3p2ZB7lOeKTBCNqMmgZsKt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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