SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45b872746abb45f3228aee960c624325b599127cdc521fae41f7989c9a692cab' 
  AND token = 'SKwIT6Vo6xivEDCAtPF0zbwunXsXAQbzEmN4bbQwJqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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