SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54acdfbae54f9c6d814b17cfddb0b731453883e80a8a70eaaf32f2e9ae330ab1' 
  AND token = '/KM+ThSUM/OFffNeN4KUwev+2tOsqz7BPlmOShiCTbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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