SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c6c1b8269c91817ba754cf43456f306534b0219336b5caafc98c715352c3379' 
  AND token = 'a9yIDJvsPzCkXtBZXpbV2cqpKA3OwsGh/IYC9RPH0xI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00085

JSON explain

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