SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd92fb15527d3f1745f800e390a50ab5c7a66c4fda74a6f4391066a59c00c4e9' 
  AND token = 'ggYBY4fk8snLMa8JgDvOaIolzIB3uOdvo6oeQmk//aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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