SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43fd216652237107ee9627e2cfeaa780be7e29b01abf57dcadd1e39c609f79ed' 
  AND token = 'xcDwUBQvvlQyUOvIOSkPzJDGFyMFUVRv7RYb6seA0RU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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