SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc71b2e4df17752433019533b1b7157a7db57749ddf648f75ccef7116004a8de' 
  AND token = 'LdbXDQvwlPMgabPvwG9TUrDgy7XiP/m9WlHQSif3oUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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