SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbf928e93db1e7b58b8058748638f7283b352af842037d0a2a83c61ccc71b128' 
  AND token = 'J2gA2HXpuJdS61o/afSPd3PCA2RHdm3mq1FBzPqQOSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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