SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ad3e37a3d1f5837192b2a2ec6fef48a6e20356df7f4b6037fe3a7f11562ff450' 
  AND token = 'wuOnYye3f7cJ5QSzenQtzNdobK+poosDnd64XmBTL0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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