SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '199594daf362a2057741b7359fc51aa5ca9b34cf17939848a741abee62c4a587' 
  AND token = 'iOPh3VBibf8zRuQbdnYJw4gTKjLKl2btZlSqbp8EVmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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