SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ccc8df49c77c9c8845f11953163518b3eb1b7870d876957e4cbad930e820674' 
  AND token = 'FqzzojoH+q/f/54aSAUa+rdV2wUddQ0TU1WhMqrgkkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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