SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adb8a2f81447c81830574bdd2d627aa8e7567615557a06ed434b394dd80a37b0' 
  AND token = 'Y60v8NqNt8JYNF0KCHlpGOSercjXid/O/DcKPQ0RHtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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