SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8611233de213fff2162742f7bdea8022ff4889b49fe37ed2ddb399f448471997' 
  AND token = 'c9O0bl3PX6PfqZFzov98dxUwSqoyvJkhBSF3epEZTHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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