SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53d9e3ece8379997fc1c53a387f5c25fad1358b05499bcd612583acb472bd192' 
  AND token = 'nDTEBDAzI+UfDY+u9xKssRhnHJX+CezEYxkvr2HVEeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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