SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a883ce803e2462da921f6ba2df3a8fbf23b255728dd856e7956412295db4fed' 
  AND token = 'oVQBCrmAypXC9TI5Kv3o3bX4ybbcSLvVhENELCOkGaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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