SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65e147f9676f98ead470c5ce598ee3515f43f126191717b18edb0377359ec173' 
  AND token = 'zHeQW9d3clmxVXiOAep93J4HoRlRYesG9FAHAnrPnK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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