SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '916b058481ee34c91b24e374cc55bed3023fa21ed3e6ce94cff318c538721909' 
  AND token = 'p7kGXNV50F4mSv2Qts/q+RfcgdK8GBKzyTLGYJok2go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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