SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73cd1f790b403e6c7987deb9fbe3d9b90ab4659d51b7c42baf957ac5709fe389' 
  AND token = 'MonQtMh2Hp+7YWBXhKaO/7LZdpskZyAwp/Vnu2Vmz1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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