SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00c8e5ae371b1c3ab7d98a95995d2e29ccf3ce33537b97ecbe2ccd28ac959855' 
  AND token = 'aBDtBGiwkx+iUUV/zN1fDJTYmEdsYaEUxLJ4OWnsCzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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