SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08dd46894440749265ab381dc58f46a48390cff662d52481c93b3ecafb02a70d' 
  AND token = 'qIZg0x8yG7wjADS57hK9e484VHMVkAQUIuYUxdwX2Q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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