SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed0b22c02afe670680177bb3fd8202fcbe16119d41b65dcc14f2ab61d11cc709' 
  AND token = 'mqirwiqeYWLftsroJZJjb0cWk8EVMPQJ2/sSkVXTlTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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