SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ed39042f1f33618fd14dd255e9d818bc24d5f76f2e9cc076bfa67a03e4c8fc6' 
  AND token = '1gBzikNS/bK7eAgfjLZVz+sg+TfYhkdcbkn+aKRufxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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