SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '605c475c5eaaf5098b1e609afafb7b00f713d3ca80219774f191b1173581dc2b' 
  AND token = 'p7LXOWa3ZQARVpcxJ/1I6RQK9dTVKcTZLzkzQLNJgHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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