SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7be74d1e58ad42faabea9db31715fc93e903e4ae0351cb32938d44e525c11cb5' 
  AND token = 'D9CNsOmqWcbsgKNZhiBj9Pw6YUzjCMt5mKehTiH97Zs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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