SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca5216d2cf9e03591b23f014ea6fa8943198114edc2cc3d90a153d4c70b152e9' 
  AND token = 'Yk3W3bF/rQsM7O5UQAvrnzG18CnGqavOcPcldKcdpl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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