SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8d040ce07c87ce72d815d02894d76dc24bfc1f8367f872ca74405d28e2542b5c' 
  AND token = '9M66di7KAAXWxlJLjqYNGDeBOHRTGZzvVLNPlcH07zM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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