SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ff32b5320681d7784fc6cdbfe212e67e73596a5585d3810da6eb9586c3081f4' 
  AND token = 'bX2gSPBYWXapZyBhwSKGutq6uBkNDKGD3izhA697u6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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