SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5036732d994b28664a1e72e65bd5f89a10166c759217ef63eb849ba06086350' 
  AND token = 'e7kUK5iSDZFWgkJHHB4v89QI/KVVjuPW//VVf9C/4UQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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