SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaa4b29ef1e144dfef7fc81ca03dea39abc0f2eeb6433da1a9ef1fcb0ecafcca' 
  AND token = '67ABvLfqav5sN1ZWtAVtYF+lOik7VpHHUBToS0I1N84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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