SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '648b3415ea1028ac62019ade308bc1de863c34453120f32cc7cbc4455361c813' 
  AND token = 'FV7v6RhuyHnJ5YKm3cxkY7hyCaJ+7QX2pocPE6dVfJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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