SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'acee9eab58d10e4c169d5799b40a13af0432fd5802a120246880798d3d1d0887' 
  AND token = '6Z9s238lTBzGpsFxb30I5BIQGKmzkZybQRI6C1WcSeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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