SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e870d97361c354be4418f3e783f3f004a28799a7134d8323708062ebda0532e5' 
  AND token = '4Py5z/Si5yoUgC7aJcfurZIoYp0Z6ZFgME+9KoF7qDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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