SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5db085d9c0ebde9247a3eaa189f7312c52ad26c9d879883d8f4d3829baabb4f5' 
  AND token = 'WRLpOMH+TB97IjNarokp2y1IAScyZrBKWYQDpjllcQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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