SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9836d4ae635277243f444d1438868a2661b21817e34d01d465fd226e6fab5816' 
  AND token = 'gVxQOirAEJJ2wLAP1QTfKX8BxjbahcYt/WHhH6WURRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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