SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '985ba838983f34b811f0fbae3bd78d8fd6996af14d1ca8e33783242446e1825b' 
  AND token = '9Xe4EYn/Oqe0s6Lj0TiYq3HHks3pzjXNjax/FII21F0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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