SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3055d5a0491fa5cb56a883fc4a90977120a8290aac8d460f6b5517760ee87c8a' 
  AND token = 'hq1KX/S7ZlXG7/JygV+uW6jS3U7lCf+vTmqDUZRbpFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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