SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '135fbbb2ac722fc30547ed7daa4ac3f4f482b1ca2097ceeaada0a71f650584c8' 
  AND token = 'WmatoR9h/SwAAZIyevTfUXh/Pou4aiih5P0SqhgkfsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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