SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '457a2d4fb001f468bcd77ad2c43774e9cdbdd650fd3c7ad1a0f513f21a113cce' 
  AND token = 'KJxU4yWQQMxIbmax3wz0/DfviHC+onjAPrpqqneCyBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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