SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b303d2653bfee0b2fb33dddb571aff681eca1c7621d2078f8b4a5adf7ccb959' 
  AND token = 'zvnPZ8Hok7ORRGnIW0eSSbogNw9Dt5oOn4GpwQ3zViQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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