SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2493a961e76d9178edadbb43281ccdbcf4d20c7d34d9b0f71eaa679d4e7f9d04' 
  AND token = 'xVBCGCKjVBBgCHmPvgr/1d5Fb8a/UCK+Hl4TF6sQktk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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