SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37957cbff5241ea1a8d18ac5cd6c4842069b4b4fd0062db2ca83a06acd056999' 
  AND token = 'ielNIJx6pK9RviPqNpsozvxZdFNtHZ0RBltbd7kf1FA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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