SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1597f94e9aff9b1875082f483cc14a4cb7c43a0bdaac64b4042adc52a917b158' 
  AND token = 'nLTXVgyZN70G7B0UKQ/DJOjpBv76AeocFpnhtXLTZRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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