SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fc8b23e536609c992e920f2855d946b6ec3367388f29c851743a0c3bba6bacd' 
  AND token = 'tqE59EWlQHVLa92Sn0ipsQGSCtbuDDm87w8MPnpZrzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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