SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '818e925bd016de0b02d21f7005209c8f98d611d04d3459f03eca40b2bc719a8d' 
  AND token = 'KXlgjf9GXYt1BXppsJ6lIzh6YGy84OnoReJIsppDmvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}