SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ac997adb1ced3259a90abef73cab5e48900e0f602f2a1178585e57928232028' 
  AND token = 'qpYgdDhUwQ9UJglx5IOS/zsdbHNbev85IQfoKwpjvw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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