SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b841817fbefb31366af5f7a3ff5c17ed4ccb244c4690bd927f6cf056ed12fed' 
  AND token = 'G48ucar6cbfvMbEZAst+XvH+8i7R49yfMJw4OUMnnK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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