SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e05518a4e6ded1ca301b08aeedc57b6c9adf497a85184cbff74d89fced919ed0' 
  AND token = '8CZQYvcXRhZntG6Q9cdTphJa3jwDujmhQsHzMzqqFtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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