SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2717ba1f20bad2b51cbb3b038f6b88058fde4c513f6239267ad911675ec4c369' 
  AND token = 'qKWFyoqK3JlgIbW0q4xK048JGRfuLtLaBNpYxhCF/Jg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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