SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfcbb2e46664c72d0c262f2ddcac35ab737c21f995ab334f4dff392b257569e4' 
  AND token = 'SQrB8gxqL8NviiVU4y5LJ/GjbpJCDoz9RqMF65CxGsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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