SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f6b41e16804169594f31772ecccf55d31e2446be196dea6c08d31b51915e56c' 
  AND token = 'WWOgabxOzIQPOPtKeOIxCsEAqSIlXkmtcJdZcdwOd8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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