SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '726721d3fa45757016b886b772ebf076f31349889f66950631f00a65b3cab9ed' 
  AND token = 'wKgloti0Q/TJ9vCLm454X+4xauQQoVCRdXBpXw8Px0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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