SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ecea5731672961cf35c222080bfbe0794726efcf597c731ba31efd8953f5b16' 
  AND token = 'fQJDbaADKcpAwLyuZlWB9Vs40O4CvCUzFeLJbODQ9W8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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