SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86443d04b8c24f69bf326faf71955e822cfce3fc6088e68a1a7f71ac96f5e1f3' 
  AND token = '38brHFaQAlFs/EuBwvOUKsIfXq6A8I7jV/0Tm+G6ZLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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