Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '998e2c57e9288bbe6e40a445c4b673e7e398a9c3032de1458c44e5574d0625b4' 
  AND token = '2DT1JRgE3BeF3upCm9jjTaLNIqm+kRB3tqdHBhOHWcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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