SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6d65fff0c52d9ceff03a1a18a3e30cf702fcabe5421ef4a75e1ab4f2427f65f9' 
  AND token = 'aKO8plyMiVApiVBMV+B/6nJZ5Uu6v7VRrOgAwX1ZjlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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