SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '112896c3245647b9a4b880921c318579796d400780323203b057642a284686b7' 
  AND token = 'Xmmi+/rKRC+HvI4OUoRoYJaDy/BQ1eE8fCx16mfNX7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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