SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7e4891a96295bc8d2b799596dac64019d54319b20d1edcf226c632671ab7828f' 
  AND token = '66SnmO/4simKVo9kALFggEReoKZO5ZvFJZ10ZE82ZA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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