SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '478f8bbe5bbb98851c9fa2bc2d428ccb6bc3766e02f7f98cd3de167dd5402240' 
  AND token = 'xTNejMAENq3ajQaBtaHG9hy1sBD9BKovklZhUKpRB9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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