SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1557346f8c5714db6f0b008eb97bf9ab9a4850474b635130d99409ad3f12dd36' 
  AND token = '94JrEPXbWKDp/TcwxqCoyAoxusGhcfe6qH6NaNUTiaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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