SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9bcd2abaac18bb10e3fda5acc3fe23d8cb715d9febe725fc28e613870bd1d346' 
  AND token = 'RUPoYRyvodCOltZVxSKSXnZFed0j++HLIGJG/gz34oM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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