SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b824e627d1676bc836992bfe6e1eddf60754cdfbd8af5bf6be315f25bcd8ef9' 
  AND token = 'MkQH4EWuDpD122JhdeXeOnfesYwFnvMUo09E3xj3ho4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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