SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '185d99041c50646599975e2858ecf6a878e4cf5b17f5598fd880377634450b26' 
  AND token = 'P+NdqhJz+pVVixzJ4k2yohb4Xhq/8gs/rbIvSr8UJok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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