SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a1a61e253742b169c99d42f60c90d4f62207891ff5c4319b7131366b090614a' 
  AND token = '8rh+v+KriZorcE+jKiNWMCEZ5/+m5BrBvqKBxjDcOeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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