SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8502f15bf73c8147c0d8cb1df31716c89c354868eb727230d875fa92961df48' 
  AND token = 'l8E/nIK5YVhZuEsBBFjv7R5K3XYpp8utJIZa7d/UaRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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