SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49125f7653a26a62373000c36f4eefebbf23f0cb76934405a4a313e697d07bca' 
  AND token = 'A4Fng+EMuKUAIZji4S/CHotzDipmEJKDYsjX8r+S8Vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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