SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b40734084dc6870dd3686de5393f82475036d40d6caf404b3429a8d995fb1a' 
  AND token = 'g3GcDksqaYIsQPs+y+RxpO8xWsNeLEAyJt4Tzw5+/Qg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}