SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46240a36b609550db6646088d7768ef748f96cc93f5d0d8ec726bdfe25b6ef4b' 
  AND token = 'AYVNHDAuWcRYoFBAYdorMBfKAF8LaMI9yodXGYhoJyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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