SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6848fd6bcb480e47adfc8ea7b4b83c2f4f623cc27b71d92fdbc44a30707fa30d' 
  AND token = 'XIvBYea6TatHb/SswiN8i3ypeQg1V63cQmizWyqB0j0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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