SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04506ea0ccfcdb359a5e2bb7742d5e569c397f928b4b2694605f88f95e4391ca' 
  AND token = 'NcGYyPsTvQJBahHGWD3uDtoNO8lVaqHlkK0qABb7oGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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