SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2df743a351eacd69afc092cd3f14b71dd08b17c9ed7fb431d0b524f95bf14e8' 
  AND token = 'OyzbiN8UkD8tg5Byd8eaiSQql58kF5K9n9izGZ/Malc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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