SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd97b43fd24d330299d1b632ef62bcf5ec0d8c145bb59cb705781891ab6b8ebf' 
  AND token = 'A29tWVg+9ziZKJVLTTP0xFNkdHjlnNcSw8LJnG7DmI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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