SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe4d3b9afb466b085a785ff0456738a8284d6ddc5de9f5ffd0fa27cc6aa64add' 
  AND token = '3lkfpx7N1jr60rIEQLC1vePQLfO4GA2A36Vxu9FuILw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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