SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44cbe5561b134ab7192c821543bac0d6fe275758e2074bb736f451430915ba5e' 
  AND token = 'Oj6tFS7Z5XpzAWP9vKX/bo2rxR9T9h5gGwh1yYLiCKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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