SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13fb623902bf90cf5aaba1c6a11e99baaffdcf79e631b1d171583358ca00d6f5' 
  AND token = 'FtCKX7nGWJP8lqhRgO/DFitl2zjzoOcDLJYSUgWAQGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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