SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9766474153f191f3adebc171e26efd50c48dd08f8cdb8f87d7c24fbc39b6bdc4' 
  AND token = 'dut5m/cRWPFM+Do9gPRlwCUdZVzn9fFJCu74zClLhnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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