SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e3b5e6ae9030b659f9efe1aa46e03bc32cb29a81da1099e6c6d787ab01f8332' 
  AND token = 'kSX7v24PeKbHJqoNnQidZ8ZrQkwhLoDZVKgOApEyMRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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