SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4dc6d0e1bcddc7fb5ab627dcf339115f2afcebf1d5f19d6a1b6c600c4034385c' 
  AND token = '+4tjigqM55pGGuZ9pHnWO7uBw8/2ykJt0erZgjA3jgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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