SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5add6353c530b728f28fbdf23c949ad21bb6a00196b144fb1b19d754617715' 
  AND token = 'HpZRz610F2CP7sXnzmpdfdr0BwslZH42XiCStSgcL6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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