SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34758be9d6ce09dc137664230f8f5cac3974f286f0ba9d0961daa27449b673d5' 
  AND token = 'tBBeLTRtEFmcMPNfXJoT5pg34OyCjXltUJo/sGZvx2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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