SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '861c20aad81ff978a5ce08bb49435c899ba28594254209f68d0bd61ba9edfca4' 
  AND token = 'vMgpuilXZdhlqmkTHRUVGg9YAf0TEQQSrhqF2J/cTIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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