SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ea6c6edc12f437c1fc825c4bfac23422a30e878278215c8665bcc6492d975a9' 
  AND token = 'lAFnL0HUJKiZIwzGj8iv6GaFOR01NbHUzlPsD1yMTGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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