SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70fd658178c7d6b79d392c5960b746bd4e9720abc1862ed3c16117cbcf5442ca' 
  AND token = '/tYnddlyAqbMSC1VqABonEZHWLEdqzc72Ng1hXDcoFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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