SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bccbbe9634fca138ae184206ce2090e8d8b48186fe60e5d17cba6b1a9a6974a1' 
  AND token = 'GX1aUOZXFyU/qZxHzKcRCRIZUUXJ5CaHFHv8cHXRT8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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